PB88-163704

NATIONAL CENTER FOR EARTHQUAKEENGINEERING RESEARCH

State University of New York at Buffalo

LIQUEFACTION POTENTIAL FORNEW YORK STATE:

A Preliminary Report on Sitesin Manhattan and Buffalo

by

M. Budhu, V. Vijayakumar, R.E Giese, and L. BaumgrasDepartments of Civil Engineering and Geology

State University of New York at BuffaloBuffalo, NY 14260

1"'echnical Report NCEER-87-0009

August 31, 1987

This research was conducted at the State University of New York at Buffalo and was partiallysupported by the National Science Foundation under Grant No. EeE 86-07591.

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NOTICE

This report was prepared by the State University of New Yorkat Buffalo as a result of research sponsored by the NationalCenter for Earthquake Engineering Research (NCEER). NeitherNCEER, associates of NCEER, its sponsors, State Universityof New York at Buffalo, nor any person acting on their behalf:

a. makes any warranty, express or implied, with respect to theuse of any information, apparatus, method, or processdisclosed in this report or that such use may not infringeupon privately owned rights; or

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50272-101REPORT 'DOCUMENTATION/I. REPORT NO. /2-

PAGE ., NCEER-87-00093. Recipient's Accession No.

Pa18 1 6 3 7 0 41A!4. TItle and Subtitle

Liquefaction Potential for New York State: A Preliminary1--~~~"":"":~~:':-----1

Report on Sites in Manhattan and Buffalo

M. Budhu, V. Vijayakumar, R.F. Giese, L. Baumgras9. PerformlllB Ol'l(8nlzatlon Name and Address

National Center for Earthquake Engineering ResearchState University of New York at BuffaloRed Jacket QuadrangleBuffalo, NY 14261

Same as box 9.

8. Perfonnlne Ol'l(anlzatlon Rep\. No;

10. ProjeCt/Tnk/Work Unit No.

lL Contract(C) or Grant(G) No.

(e) >ECE-86-07591C 86-1022

~

13. Type of Report & Period Covered

Technical Report

14.

15. SUpplemental)' Notes

This research was conducted at the State University of New York at Buffaloand was partially supported by the National Science Foundation.

16.~ (Umlt: 200 wonts)

The chances of a major earthquake occurring in New York State in the'nearfuture is low. However, -historically New York State has experienced andno doubt will continue to experience moderate earthquakes with a maximumModified Mercalli intensity of VI. At these intensities,'-catastrophicdamage due to structural causes is not likely to occur for 'non-masonrybUildings, but ground failure due to soil liquefaction is possible. Liquefactioncan cause substantial damage and losses as demonstrated by the Alaskaearthquake of 1964 where 60% of the estimated $500 million total losswas related 'directly to ground failure. For this project, nearly 6,000 boreholelogs from the two selected sites (upper Manhattan and downtown Buffalo) werecollected, stored in a computer database and analyzed to determine the lique-

. tfaction potential of the soils lying within 50' of the ground surface. Theprocedures which were used for this analysis rely heaVily on standard penetra­tion test numbers and the ground water elevation in the hole. Liquefiable soilsare typically loose water saturated cohesionless materials. It appears fromthis study that,for the design earthquake de.scribed above, areas which lieadjacent to bodies of water (the Harlem River in Manhattan and Lake Erie in'Buffalo) are liable to liquefy.

17. Ooc:ument

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LIQUEFACTIONNEW YOUR STATE - SEISMICITYLIQUEFACTION POTENTIAL

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l----:u:.:n..:..:c:..;l..::a=s.=.s.:.,if.:...,:..::·e:.:d:...-__-+ :.--~_20. Sel::urlt)' <:I." (ThIs Pece)

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LIQUEFACTION POTENTIAL FOR NEW YORK STATE:

A PRELIMINARY REPORT ONSITES IN MANHATTAN AND BUFFALO

by

M. Budhu\ V. Vijayakuma?, R. F. Giese3, andL. Baumgras4

August 31, 1987

Technical Report NCEER-87-0009

NCEER Contract Number 86-1022

NSF Master Contract Number ECE 86-07591

1 Assistant Professor, Department of Civil Engineering, State University of New York atBuffalo

2 Graduate Research Assistant, Department of Civil Engineering, State University ofNew York at Buffalo

3 Professor, Department of Geology, State University of New York at Buffalo4 Graduate Research Assistant, Department of Geology, State University of New York at

Buffalo

NATIONAL CENTER FOR EARTHQUAKE ENGINEERING RESEARCHState University of New York at BuffaloRed Jacket Quadrangle, Buffalo, New York 14261

ABSTRACT

The chances of a major earthquake occurring in New York State in the near future is low.

However, historically New York State has experienced and no doubt will continue to experience

moderate earthquakes with a maximum Modified Mercalli intensity of VI. At these intensities,

catastrophic damage due to structural causes is not likely to occur for non-masonry buildings,

but ground failure due to soil liquefaction is possible. Liquefaction can cause substantial

damage and losses as demonstrated by the Alaska earthquake of 1964 where 60% of the

estimated $500 million total loss was related directly to ground failure.

In this report, liquefaction potential maps for two urban areas - a region in upper Manhattan,

New York City, and a portion of downtown Buffalo, New York - are presented. These maps

show the probability of liquefaction for ground shaking induced by an earthquake of magnitude

7.5 and a peak ground acceleration of 0.15 g. Such maps are invaluable for earthquake hazard

mitigation projects, especially in questions of land use regulation and in preliminary emergency

response planning.

For this project, nearly 6,000 borehole logs from the two selected sites were collected, stored in

a computer data base and analyzed to determine the liquefaction potential of the soils lying

within 50' of the ground surface. The procedures which were used for this analysis rely heavily

on standard penetration test numbers and the ground water elevation in the hole. Liquefiable

soils are typically loose water saturated cohesionless materials.

It appears from this study that, for the design earthquake described above, areas which lie

adjacent to bodies of water (the Harlem River in Manhattan and Lake Erie in Buffalo) are

liable to liquefy.

Although the procedures used, in particular the standard penetration test, are open to question,

the results of this study clearly indicate those areas in Manhattan and Buffalo where there exists

a real possibility for liquefaction. Based on this study, suitable emergency response programs

should be instituted.

i I b

SectionTable of Contents

Title Page

ABSTRACT .

1 INTRODUCTION.............................................................................................................. 1-11.1 General 1-11.2 Scope of Study 1-2

2 LIQUEFACTION EVALUATION.................................................................................... 2-12.1 Liquefaction 2-12.2 Evaluation of Liquefaction Potential 2-22.2.1 Geological Criteria 2-22.2.2 Criteria Based on Standard Penetration Test (SPT) Data 2-42.2.3 Liquefaction Potential 2-52.2.4 Liquefaction Probability 2-6

3 REGIONAL SEISMICITy................................................................................................. 3-13.1 Local Seismicity 3-13.2 Distant Seismicity 3-4

4 STUDY AREAS................................................................................................................. 4-14.1 Manhattan 4-14.2 Buffalo 4-24.3 Geotechnical Data 4-34.3.1 Upper Manhattan 4-34.3.2 Buffalo 4-5

5 LIQUEFACTION MAPPING............................................................................................ 5-15.1 Mapping Methodology 5-15.2 Liquefaction Maps 5-25.2.1 Upper Manhattan 5-25.2.2 Buffalo 5-4

6 DATABASE DESIGN 6-16.1 Specifications 6-16.2 Implementation 6-26.3 Current Status 6-36.4 Future Activities 6-3

7 CONCLUSIONS................................................................................................................. 7-1

8 LIMITATIONS................................................................................................................... 8-1

9 REFERENCES.................................................................................................................... 9-1

10 ACKNOWLEDGMENTS.................................................................................................. 10-1

11 APPENDICES.................................................................................................................. 11-1

ii

FigureList of Figures

Title Page

N60 values for clean sands leading to liquefaction 2-7

2 Magnitude normalized CSR model for soils with different fines content.......... 2-8

3 Typical borehole log description from Manhattan 4-4

4 Geographic distribution of borehole logs in the upper Manhattan study area.. 4-6

5 Liquefaction potential map for the upper Manhattan study area....................... 5-3

6 Liquefaction potential map for the Buffalo study area 5-5

iii

SECTION 1

INTRODUCTION

1.1 General

The probability of a major earthquake occurring in or near New York State is small. However,

historical records indicate that parts of the State have experienced, and likely will continue to

experience, moderate earthquakes with Modified Mercali intensities of VI or less. With an

earthquake of this approximate magnitude, it is unlikely that catastrophic damage due to

structural failures will be common, but ground failure resulting from liquefaction is probable ­

given the proper soil conditions and appropriate ground accelerations. Examination of

historical earthquakes has dramatically demonstrated the damage that can result from

liquefaction. A typical example is the 1964 Alaska earthquake where 60% of the estimated

$500,000,000 damage was directly related to liquefaction.

The integrity of a structure, a transportation system, or a lifeline utility located in an area

affected by an earthquake is challenged by two factors: the ability of the structure itself to

withstand the seismic waves and the resistance of the environment about the structure to ground

failure. It is clear that structures which are adequately designed to survive earthquakes can

readily be damaged or destroyed if they rest on or within soils that liquefy. Thus, in designing

earthquake resistant structures, it is also necessary to consider the geological and geotechnical

characteristics of the site upon or in which the structure is to be situated. Little effort has been

expended in identifying regions of the Eastern United States which are susceptible to this type

of earthquake damage.

Clearly, there is more interest in earthquakes in those states lying to the west of the Rocky

Mountains; there are many more earthquakes there than in the states lying to the east. But this

difference, while true, tends to give the eastern US a false sense of security. The two regions

of the United States are underlain by very different geological provinces. The eastern

continental US is underlain by a cooler and relatively denser plate than is found in the west.

This difference allows seismic waves from earthquakes to travel greater distances for a given

1-1

attenuation in the east than in the west. Hence, a moderate to large earthquake in the east

affects a much larger area than an equivalent earthquake in California. As the area which is

shaken by an earthquake increases, the possibility of ground failure also increases.

In the western United States, the relation between geology and earthquakes is well established.

The sites of major earthquakes are associated with fractures in the crust and the movement

along these fractures is ultimately driven by the movements of the major plates. This simplifies

the search for areas of potential ground failure. In contrast, earthquakes in the eastern United

States are rarely directly related to known faults. The existence of fractures at depth is

becoming clearer. But there is much about these deep and old fractures that is unknown and

unpredictable. The uncertainty, therefore, puts much larger regions in the east at risk. In order

to reduce this uncertainty somewhat, it is essential that those regions which have the potential

for ground failure be identified. Once identified, it should be possible to design structural

codes so that the damage due to the next large earthquake can be minimized.

1.2 Scope of Study

Three tasks were identified for the first year of this project. These were-

Task 1. Collect subsurface geotechnical data from previous field investigations oftwo restricted sites. These were chosen to represent two types of environmentin New York State - a large and a medium sized urban region. The siteswhich were investigated were in upper Manhattan (approximately 6 mi.2),New York City and the central part of Buffalo (approximately II mi.2).

Task 2. Develop liquefaction potential maps for these two regions, identifyingthose areas which have a high, moderate, or low probability of liquefactionfor an assumed acceleration. The evaluation of the liquefaction potential forthis initial study is based on data selected from the information assembledduring Task 1.

Task 3. Design and implement a database system capable of storing the largequantities of geotechnical and geological data generated by Task I. Thisdatabase will ultimately provide the information necessary to accomplish Task2.

1-2

SECTION 2

LIQUEFACTION EVALUATION

2.1 Liquefaction

Liquefaction is a phenomenon by which saturated soils - essentially cohesionless soils - are

temporarily transformed into a liquefied state. In the process, the soil undergoes transient loss

of strength which commonly allows ground displacement or ground failure to occur.

Liquefaction in the context of this report implies liquefaction induced ground failure, because

the assessment of liquefaction adopted for this project, was derived from observed ground

failure data.

Three basic types of ground failure are associated with liquefaction.

1. flow failures - soil materials flowing rapidly downslope in a liquefied state.

2. lateral spreading - limited displacement of surface soil layers down mild slopes.

3. loss of bearing strength - bearing capacity failure of foundations because ofweakening of underlying or adjacent soil material.

Liquefaction can also cause transient horizontal oscillations as the ground surface layers are

decoupled from more rigid material underlying the liquefied layer. Such decoupled vibrations

can cause severe damage to buildings, pipelines, and other structures.

Of specific interest to this proposal is the liquefaction of soils under stress conditions induced

by an earthquake, either close by or at some distance. Past experience has shown that seven

factors are important in determining the potential for a particular soil to liquefy. These are 1)

age of the soil, 2) depth to groundwater, 3) the grain sizes present in the soil and their relative

proportions, 4) density, 5) origin of the soil, 6) thickness of the soil, and 7) the acceleration

experienced by the soil.

Age: Weak, cohesionless soils are typically young. With time, two factors act toincrease the strength of a typical soil: compaction changes the void ratio, andvarious chemical processes act to cement the soil grains together. A rule of thumbis that deposits older than Late Pleistocene are unlikely to liquefy except under themost vigorous conditions, while Late Holocene deposits are most likely to liquefy(Youd and Hoose, 1977).

2-1

Groundwater: Ground water acts to reduce the bearing strength of a soil bydecreasing the effective stress. Hence, the higher the ground water table, the moreextensive will be this effect.

Grain Size: The type of soil most likely to liquefy is one which has apredominance of sand sized particles, with little in the way of fines or coarsergrains; a good, clean sand. Silty sands and gravels are also susceptible toliquefaction under very severe cyclic loadings.

Density: Liquefaction occurs principally in loose, saturated, cohesionless soils. Sucha soil will densify when subjected to cyclic loading. This tendency to densifyresults in an increase in pore water pressure if the intergranular pores are filledwith water. When the pore water pressure becomes equal to the total mean stress,the soil loses its strength and liquefies. If the soil is dense to begin with, there willbe a smaller opportunity for liquefaction.

Origin: Soils which are deposited by fluvial processes are deposited rapidly andhave little chance to achieve a dense packing of grains. These will liquefy easily.On the other hand, glacially deposited sediments, particularly those over which theglacier has passed, are generally rather dense already, and are less likely to liquefy.

Thickness: To create substantial damage during liquefaction, the soil should be thick(for horizontal strata) so that the dimensional changes which occur will besubstantial.

Ground Accelerations: The ability of a soil to withstand the accelerations due to anearthquake depends on the magnitude of the acceleration and on the duration of theshaking. These can only be estimated, in general, by looking at records of historicalearthquakes.

2.2 Evaluation of Liquefaction Potential

Over the past decade or two, efforts have been made to establish a scientific basis for the

prediction of liquefaction under earthquake conditions. From this work, two different

approaches have developed: one based on essentially geological characteristics of the soils, and

the other relies on geotechnical measurements of the soil.

2.2.1 Geological Criteria

Youd and Perkins (1978) developed a method for the construction of liquefaction potential

maps. In essence, this is done by combining information from two different types of maps for

the same region: a map showing the liquefaction opportunity, and a map showing the

liquefaction susceptibility. The former is derived from the seismicity of the area; the latter is

2-2

determined from the geologic age of soils and the depth to ground water. In theory, the greater

the seismic activity, the younger the soil, and the closer the ground water is to the surface, the

greater will be the liquefaction potential.

As a general rule, young detrital sediments (or soils in the engineers terminology) are weaker

than older equivalent sediments. For example, sand deposited by a river or ocean currents

initially lacks cohesion. With time, the strength of the sand is increased by a number of

processes: compaction due to burial, the precipitation of mineral phases from intra-particle

fluids, and the slow dissolution and reprecipitation of the material of the grains themselves.

Typically, sediments which are most susceptible to liquefaction are late Holocene (1000 yrs or

less), with early Holocene having moderately liquefiable, and late Pleistocene having a low

probability of liquefaction. With the variety of processes which can take place in geological

materials, it is to be expected that exceptions will be found.

Similarly, because water saturation is necessary for liquefaction, depth to the water table is

important. A second factor enters here; the increase in the strength of a soil as it is buried

deeper. For these reasons, the most easily liquefiable soils will be those which have the ground

water lying within 10ft. of the surface. As the depth to the water table increases, the

likelihood of liquefaction decreases.

These criteria have the advantage that they are easily applied to a variety of geological terrains,

and they require data which is normally already at hand from routine geotechnical borings. A

weakness is the obvious one; they are strictly qualitative. To date, several regions, mostly in

California, have been investigated and liquefaction potential maps for them have been

published. These are-

2-3

Davis County, Utah Anderson et at. (1982)

Los Angeles, CA Tinsley et at. (1985)

San Diego, CA Power et at. (1982)Idriss et at. (1982)

San Mateo County, CA Youd and Perkins (1985)

San Fernando Valley, CA Youd et at. (1978)

San Francisco, CA Roth and Kavazanjian (1984)

2.2.2 Criteria Based on Standard Penetration Test (SPT) Data

The standard penetration test, though widely used, is acknowledged to be an extremely crude

procedure. The name is a misnomer because there is nothing really standard about the way the

test is performed, and the necessity of converting from one set of conditions to another is

fraught with uncertainty, even though there are conversion factors available in the literature.

In the United States, there has been an attempt to codify the conditions under which the test is

performed, and these are described by ASTM 01587-67. The existence of an ASTM standard

has not in the slightest prevented the continued use of a proliferation of different tests in the

field. According to the standards, the test consists of driving an 18" split tube (2" outside

diameter with a wall thickness of 5/8") into a soil by repeated blows from a 140 Ib hammer

falling onto an anvil attached to the top drill rod, from a distance of 30". The number of

hammer blows for each 6" of penetration by the tube is recorded. The standard penetration

number, N, is the number of blows required to penetrate the last 12" (of the total of 18"). This

N-value is sensitive to a number of factors which can vary from site to site and even within the

same site: the overburden pressure, lateral soil pressure, and the density of the soil. It is now a

common practice to correct the N-value for these variables to yield a presumably unbiased

number, (N)60, which is equivalent to a hammer energy ratio of 60% (Seed et at., 1984).

Many variations of the SPT test have been used, particularly in the past. Variations occur

principally in the size of the split tube, the drill rods, the driving technique, the weight and

2-4

type of hammer, and the height of the drop. Studies were conducted (for example, Lowe and

Zaccheo, 1975) to correct the N-values for these non-standard tests to the ASTM DI587-67.

We will refer to this standard in this report. Lowe and Zaccheo (1975) proposed a relationship

which accounts for variations in hammer weight, drop height, and the diameters of the split

tube. Based on an extended series of field tests, they showed that there is a linear relationship

between hammer ratio, Rs , and the N-value. The hammer ratio is defined as:

(I)where Do and Dj are the external and internal diameters of the split tube (in inches)

W is the weight of the hammer (in Ibs)

H is the drop height (in inches)

This equation does not consider the dynamics of the hammer. It appears from the data reported

by Lowe and Zaccheo (1975) that for cohesionless soils at relative densities below 50% (which is

appropriate for liquefaction studies) the following conversion is sufficiently accurate for

practical purposes.

N = 4050N R S/7

e s(2)

where Nand Ne are the actual and corrected standard values respectively.

2.2.3 Liquefaction Potential

Seed et al. (1984) proposed a method of evaluating the liquefaction potential of soils on the

basis of field observations. They showed that for sites in Pan America, Japan, and China where

soils were observed to liquefy during earthquakes, the liquefaction potential of clean sands and

non-plastic silt is related to the (N)60 value.

Their procedure for evaluating the liquefaction potential is:

I. Establish the soil conditions and choose a design earthquake.

2. Compute the average shear stress ratio Tav/Uo (where rav is theaverage shear stress and Uo is the effective overburden stress) forthe maximum acceleration (amax) of the design earthquake fromthe relationship-

r au / a 0= 0 .65 (a max / g ) (a ~ / a 0) r d

2-5

(3)where g is the acceleration due to gravity, O'ot is the totaloverburden stress, and rd is a stress reduction coefficient whichvaries from a value of 1.0 at the surface to about 0.9 atapproximately 35' depth.

3. Correct the Ne value to N60 using the equation­N 60 = C nN.

(4)where Cn is a correction factor equal to 0'0-1/2 (Liao andWhitman, 1985).

4. The presence of fine particles in a sandy soil strongly influencesthe liquefaction potential. The possibility of liquefaction for agiven fines content, N60, and Tav/O'o is determined according toscheme shown in Fig. 1. If the coordinates (N60, Tav/0'0) lieabove the appropriate fines-content curve, the soil will liquefyunder an earthquake of magnitude 7.5. Correction factors havebeen suggested by Seed et al. (1983) to yield curves forearthquakes with magnitudes other than 7.5.

The procedure does not account for the duration of shaking during the earthquake.

2.2.4 Liquefaction Probability

Liao et al. (1987) proposed a probabilistic method to evaluate the liquefaction potential using a

regression analysis of SPT data from 278 sites where liquefaction was observed to occur. They

worked with two models: one, termed the CSR (for cyclic stress ratio) model (Fig. 2), is similar

to that of Seed et al. (1984); the other, termed the source model, makes use of earthquake load

parameters, viz magnitude and epicentral distance. The liquefaction demarcation curve of Seed

et al. (1984) corresponds approximately to a 50% probability for the occurrence of liquefaction

as formulated by the CSR model.

The major advantage of the work of Liao et al. is that the liquefaction potential of soils can be

cast into probabilistic terms. Thus, one can construct a classification scheme where, for

example, the letter H (for high) used by Youd and Perkins (1978) can be associated with a

specific probability for liquefaction; one that is greater than 50%.

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SECTION 3

REGIONAL SEISMICITY

The eastern United States is an intraplate region with normally a moderate level of seismic

activity. Historically there have been very large earthquakes, but these have been sporadic and

few in number. Nonetheless, the severity of these big earthquakes and the fact that the energy

is dispersed over very large areas, makes the subject of seismic activity an important one.

Western New York experiences the arrival of seismic waves from many sources. For the

purposes of the following discussion, we will distinguish between "local sources" (within the

New York State and southern Canada) and "distant sources" (anywhere else in the eastern United

States).

3.1 Local Seismicity

Examination of the seismic activity in New York State and adjacent areas during the early 1970s

(Sbar and Sykes, 1977) showed that, at least for this period, central New York, much of the

Adirondacks and neighboring areas of Pennsylvania were essentially aseismic. The active areas

were restricted to four zones: a zone from Boston to central New Hampshire, a zone from

Kirkland Lake (Ontario) to northern New York, a cluster of activity centered on the towns of

Attica and Dale in western New York, and a region northeast of Quebec City (La Malbaie). Of

the two regions in New York State, the Adirondack zone is more active presently than is the

area around Attica. Historically, this may not have been true.

From a study of fault plane solutions, hydrofracturing, strain relief stress measurements, and

deformation of recent origin, Sbar and Sykes (1977) postulated the existence of different stress

domains in the eastern United States. One region extends roughly from Hudson Bay in the

north to the edge of the Mississippi embayment in the south. It may extend as far east as

Vermont and the westward limit may continue until the Rocky Mountains. Within this stress

domain, the dominant orientation is ENE, and the stress is horizontal and compressive. There

are indications that the stress is uniform from the eastern border of New York into Ohio and

southern Ontario.

3-1

Of particular interest to this proposal is the seismic activity located in western New York

region. The major event was at Attica on August 12, 1929. This had an intensity of VIII (MM)

(Coffman and Von Hake, 1973; Smith, 1962), but there has been a tendency to lower the

original estimates to VII (Fox and Spikes, 1977) or to a magnitude of 5.2 (Sykes, 1978).

Nonetheless, the event was felt over an area of 130,000 km2 (Fletcher and Sykes, 1977). There

have been two more recent earthquakes, January 1, 1966 and June 13, 1967, each with an

intensity of VI. A study of these by Herrmann (1978) indicated that the depths were shallow,

on the order of 2 to 3 km, suggesting that the 1929 event was also shallow. The suggestion was

made by Herrmann that the shallow depth would explain the relatively large amount of

destruction given the relatively weak nature of the earthquake. Similar observations were made

in connection with the New Madrid earthquakes of 1811 and 1812 (Herrmann, 1978).

The earthquake activity at Attica is closely related to the Clarendon-Linden fault zone. This is

shown by the close spatial relation between the epicenters of the three Attica earthquakes

mentioned above, the other seismic activity in western New York (Sbar and Sykes, 1977), and

the seismic activity associated with hydraulic mining (Fletcher and Sykes, 1977). The

Clarendon-Linden fault likely extends northward under Lake Ontario forming the topographic

feature called the Scotch Bonnet Rise (Hutchinson et al., 1979). This gives a total length of

approximately 150 km. A possible further extension to the Bancroft area of Ontario is

suggested by gravity data, making the total possible length of the fault about 250 km. This

feature is clearly a major fracture in the Precambrian crust.

The present knowledge of earthquake activity for New York State is limited (Mitronovas and

Nottis, 1984). The scientific community is not in a position to predict the next major

earthquake in New York State or adjacent regions. Neither the tectonic structures nor the

encompassing mechanisms have been identified for these areas that can be definitively

associated with earthquake occurrences (Barstow and Pomeroy, 1984).

The region we selected for study (see Section 4) is sufficiently small that the seismicity within it

is difficult to evaluate given the current state of knowledge for earthquakes in and near New

York State. However, the existing earthquake records for New York State, which goes to the

past 300 years, is probably the best source for evaluating the seismicity of the area. Veneziano

3-2

and Van Dyck (1984) and Mitronovas and Nottis (1984) in their reports on the seismicity of

New York have compiled a record of earthquake events, and an earthquake catalogue for New

York State. In addition, they indicate the number of earthquakes, the total energy released for

New York State, and the average recurrence times (ART) for earthquakes of various

magnitudes.

Earthquakes in Pan-America, the western United States, Japan, and China are presently used as

the basis for evaluation of earthquake hazards. It is essential to be aware of the characteristics

of possible earthquake hazards in the eastern United States compared to the well documented

western ones in order to realistically interpret, judge and apply the various evaluation

techniques. Hays (1984) has compiled such a comparison, the results of which can be

summarized as:

• The peak ground acceleration for the east can be higher. Ground motion in theeast has a tendency to attenuate slowly away from epicenter creating potentialto damage tall buildings far away (500 miles) from the epicenter wheredamage need not be widespread.

• Except for the 1811 - 1812 New Madrid earthquakes, no earthquakes are tiedto surface expression of faulting in the east.

• The recurrence period for major earthquakes is 150 years for California but isbetween 700 and 1000 years in New Madrid seismic zone.

• The attenuation rate for the seismic energy in the east is much slower than inthe west. This could result in damage to a much larger area in the east.

• Soil and rock columns in the east are capable of amplifying ground motion forselected frequency ranges which could lead up to a two unit increase ofModified Mercalli Intensity rating relative to rock.

• For major earthquakes, the aftershock sequence may last several years for theeast in contrast to a few months in the west

The W 125th Street fault in Manhattan could be disregarded as a possible source of ground

shaking according to the conclusions of both Hays (1984) and Mitronovas and Nottis (1984).

3.2 Distant Seismicity

Major historical earthquakes in the eastern United States generally are spatially restricted.

Events with intensities greater than or equal to VIII have occurred in Quebec (La Malbaie), the

3-3

zone from northern New York to Kirkland Lake, Boston, New Madrid, Charleston, Attica and

Massena, and a few other, apparently isolated events. Looking at this distribution (Acharya,

1980), Western New York is rather centrally located, with important seismic activity to the

northeast and to the southwest. Even though the distances are large, the efficient transfer of

energy from the epicenters over long distances in the eastern United States makes these large

earthquakes of extreme importance to the estimation of risk for the population centers of New

York.

3-4

SECTION 4

STUDY AREAS

For this initial survey of the liquefaction potential in New York State, two areas were chosen.

The criteria used for the selection were: 1) that the areas have a substantial population density,

2) they should have geologically young sediments, 3) a ground water table close to the surface,

and 4) a history of geotechnical exploration from which to draw the information necessary for

the liquefaction analysis. The reasons for choosing these criteria will be made clear in

subsequent sections. Two areas were identified: one in the upper part of Manhattan, New York

City and the other in the waterfront sections of Buffalo.

4.1 Manhattan

The geology of southeastern New York is among the most complicated in the state. Structural

features of this region include unconformities and disconformities; anticlinal, synclinal,

monoclinal, isoclinal, open, closed, and overturned folds; and normal, reverse, and thrust faults.

These many types of structural features have been caused by isostatic changes in elevation,

formation of mountain chains and other metamorphic events, igneous intrusions, and erosion.

The stratigraphic sequence found in Manhattan includes rocks of the oldest known type, the

Grenville formation, to unconsolidated glacial deposits of Pleistocene age. Manhattan Schist is a

pelitic Schist of Middle to Upper Ordovician age and is the most abundant type of rock found

in Manhattan. Inwood Limestone of Cambrian to Lower Ordovician age underlies the

Manhattan Schist and is found in a belt which runs roughly between Clinton and Second

Avenues, south of 34th Street. Gneissic rocks of the Precambrian Fordham Series are found

between the Inwood Limestone and the East River.

All of the rock formations on Manhattan have undergone folding. Most of the folding occurred

during three major periods of geologic disturbance in Precambrian, post-Ordovician, and

post-Devonian times. Compressional forces with primarily northwest to southeast orientations

were generated during each disturbance; these forces produced a series of northwest to southeast

trending synclinal and anticlinal folds.

4-1

Faulting is commonly associated with regional folding. Two major faults in Manhattan are

located north of Central Park, and have a general northwest to southeast direction of strike.

The larger of these two faults, the 125th Street Fault, runs from the south end of 125th Street,

through the northern tip of Central Park, to the north end of Ward's Island. The smaller of the

two faults runs roughly parallel to the 125th Street Fault in the Harlem River basin.

4.2 Buffalo

The western part of New York State lies on the edge of the Appalachian Basin. The surface

rocks are Paleozoic limestones, dolomites, with abundant shales, and some locally important

sandstones. The sedimentary rocks do not form a continuous Paleozoic sequence (the Lower

Ordovician is missing, for example), but all the sedimentary rocks are conformable, and there

has been little tectonic deformation. There is a general regional dip of about 40 feet per mile

to the south.

North of Lake Ontario, the crystalline basement rocks outcrop. These are metagabbros,

granites, marbles, and various mafic rocks. This suite presumably underlies the sedimentary

sequence in western New York, and the gravity anomalies in the region have been related to the

distribution of these different density materials (Hodge et at., 1982). Bedrock in the study area

typically consists of Hamilton Group limestones and ranges in depth from 0 to 60 feet (City of

Buffalo, Division of Planning, map: "City of Buffalo Rock Elevations").

Unconsolidated deposits within the study area are highly variable due to the complex

stratigraphy of surficial deposits and alteration of natural soils by extensive excavation,

dredging, and fill operations. Naturally occurring soils are heterogeneous, but the stratigraphy

of unconsolidated deposits can be generally characterized as follows: compact to dense clayey

glacial till overlain by red-brown very soft to medium stiff varved clay, overlain by a

grey-brown stiff varved silt/clay. Gradational variations are present throughout the entire area

and some units are not ubiquitous due to diverse glaciation patterns. Well to poorly sorted

sand, and/or gravel seams and lenses are interbedded among units at many locations. Rather

4-2

thick deposits of loose fine sands exist at locations in the vicinities of the Buffalo River and

Lake Erie shorelines indicating the presence of buried alluvial/glaciofluvial channels and ancient

beach deposits. The groundwater table is shallow, generally at depths a few feet below grade.

Construction sites are common in the area. Soils at many of these sites have been disturbed by

construction of inland waterways to facilitate shipping commerce in the mid to late 1800's. A

network of inland waterways, canals, and slips were built in the areas presently known as the

Black Rock and Buffalo harbors. Filling of these waterways began in the early 1900's as

alternate transportation systems were implemented. Landfilling was also performed in order to

make development of swampy areas possible. In addition to filling of inland areas, the original

Lake Erie shoreline has been extended 600 - 800 feet west of its natural position

(Goldberg-Zoino Associates, 1984). The waterfront edge is currently being extended toward the

Lake by diked disposal area projects undertaken by the U.S. Army Corps of Engineers, Buffalo

District.

4.3 Geotechnical Data

The data which were used for the liquefaction analysis came from two types of sources: drilling

done by governmental agencies and geotechnical investigations done by private engineering

companies at the request of local builders. In general, the data for Manhattan came primarily

from the public sector while the Buffalo study drew largely from the data collected by private

engineering companies.

4.3.1 Upper Manhattan

A total of 3,308 borehole logs covering the period from 1940 to 1986 were collected mainly

from the following two agencies:

• Department of General Services, New York City

• New York City Housing Authority

Approximately ninety five percent of the borehole logs contained the soil descriptions, data on

ground water level, and N values. A typical borehole log is shown in Fig. 3.

4-3

\.EGEND

GRAIN SIZE ABBREVIATIONSf _ fi". M Mediu." ( (<XIII•.

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PREPARED BY:

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SUBSURFACE EXPLORATION SECTION

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4-4

The ground water level at this particular site is very close to the ground surface. Thus, in

nearly all the boreholes drilled at this site, casings were used to support the sides of the hole.

One complication appeared during the evaluation of the geotechnical data collected for parts of

Manhattan. This concerns those areas, typically along the Hudson and East Rivers, where new

land was created by adding fill to the river banks. The material in these reclaimed sections can

extend to depths of as much as 20'. The geotechnical data for these areas are very suspect, and,

even if they are of good quality, it is still difficult to make reliable estimates of the liquefaction

potential because, at present, there is a complete lack of understanding and practical experience

with the behavior of this type of material under earthquake conditions.

A review of the borehole logs revealed that about 60% of the near surface materials (within

depths of less than 50') can be classified as silty-sand and sandy-silt, both of which are

potentially liquefiable.

The quality of the data in over 75% of the boreholes appeared to be exceptionally good. Most

of the N values, however, were obtained from non-standard tests and had to be corrected as

described in Section 2.2.2. Fig. 4 shows the distribution of the sites of the boreholes in the

study region.

4.3.2 Buffalo

The data collected for the Buffalo study area consists of approximately 2,500 borehole logs from

about 90 sites. An extensive preliminary literature search was performed using the National

Center for Earthquake Engineering Research (NCEER) Information Services Office and by use

of the on-line computer database GEOREF. Historical records documenting local effects of

past regional seismic events were reviewed at the Buffalo Historical Society and State University

of New York at Buffalo libraries. Extensive data were also collected with the assistance of

Empire Soils Investigations Inc., an engineering/consulting firm located in Blasdell, New York.

Empire Soils Investigations, Inc. project files for the years 1963-1987 were reviewed for

relevant geotechnical data. Past Empire clients owning the files of interest were contacted for

permission to incorporate these data into the study.

4-5

BOREHOLE LOG DISTRIBUTIONMANHATTAN - NEW YORK CITY

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LATITUDE (40 DEG-. NORTH +)o STUDY AREA LIMITS + BOREHOLE LOG-

Approximate scale:

Latitude 1 minute = 6000.0 ft.Longitude 1 minute = 4594.8 ft.

Figure 4. A map of upper Manhattan showing the location of the borehole logs used in thedetermination of the liquefaction potential of the area. Only the latitude and longitude of theboreholes are shown; the outline of Manhattan is not indicated.

4-6

The following agencies have also contributed to the data base:

• United States Army Corps of Engineers

• United States Naval Reserve

• New York State Department of Environmental Conservation Division of Solidand Hazardous Waste

• New York State Department of Transportation

• City of Buffalo Department of Public Works, Engineering Division

• City of Buffalo Sewer Authority

• City of Buffalo Board of Education

• City of Buffalo Planning Board, Department of Community Development

4-7

SECTION 5

LIQUEFACTION MAPPING

5.1 Mapping Methodology

The selected study areas lie within an isoseismal area. A realistic design earthquake magnitude

cannot be reliably extractable from whatever is known so far of the seismicity of New York

State. The liquefaction evaluation procedures used in this project do not involve design

magnitude of earthquakes. The maximum surface acceleration (amax) values are used in the

compilation. Therefore, the design earthquake magnitude can be taken as any arbitrary value,

since its influence is taken as uniform for the region.

For the region, a 7.5 magnitude (M) will be assumed so that Seed's criteria plots can be applied.

The maximum surface acceleration (amax) is the critical factor and is related to the M value.

Empirical relationships were established (Seed et al., 1983) based on actual field liquefaction

records between maximum ground acceleration (amax), epicentral distance (R) and earthquake

magnitude (M). However, such relationships cannot be applied to the study region with both

M and R unpredictable and with no applicable field liquefaction data available.

The contribution by Algermissen et al. (I982) deals with the peak ground acceleration at sites

underlain by rock in New York City. Since the present study area coincides with that of

Algermissen et al., their plots of maximum ground acceleration as a function of exposure period

for the New York City area are directly applicable.

From their relations, amax has a 90% non exceedence value of approximately 0.18 g over a 50

year period. Earthquakes of (MMI) intensity VI and greater are possible in New York State and

these could generate maximum surface accelerations up to 0.15 g (McCann et al., 1980).

Therefore, a value of amax = 0.15 g is not unrealistic in evaluating the liquefaction potential of

the areas described in this study.

The following methodology was adopted for deriving the liquefaction potential maps for the two

selected sites.

• Each borehole log was inspected and those containing N values less than 15at depths of less than 50' were selected for detailed evaluation.

5-1

• A latitude-longitude grid system was used to reference each site.

• The relevant data - N values, hammer characteristics, ground waterelevation, depth of the borehole, thickness of the soil layers, soilclassification (including the fines content), and geographic location - wereentered into a standard spread sheet program. An example is shown inAppendices lA and lB.

• The lowest N value for each layer was selected and then corrected to theequivalent standard Ne value using equation (2). The N60 value wasevaluated using equation (4) (see Section 2.2.2).

• A maximum acceleration, amax = 0.15 g, was selected for both the Manhattanand Buffalo sites based on earthquake records compiled by Algermissen et al.(1982) and McCann et al. (1980).

• The probability of liquefaction was obtained by using the critical stress ratiomethod of Liao et al. (1987) as described in Section 2.2.4. An average bulkunit weight of 110 lbs/ft.3 was assumed.

5.2 Liquefaction Maps

The maps were produced for an earthquake of magnitude 7.5 and a peak ground acceleration

0.15 g. As mentioned in Section 2.2.3, suitable scaling factors can be applied to yield the

liquefaction potential for different magnitudes.

Each of the two sites investigated presented special problems. The results of our preliminary

analysis are presented below.

5.2.1 Upper Manhattan

Fig. 5 shows the liquefaction potential map generated for upper Manhattan using the procedure

described in Sections 2.2.3 and 5.1. In view of the great uncertainties involved in the estimation

of the liquefaction potential, the final calculated values were grouped into three categories and

these are the zones shown in Figure 5. The categories are arbitrary but they were selected to be

consistent with much of the previous work in liquefaction potential mapping.

H high; probability of liquefaction> 50%

M moderate; probability of liquefaction 10 - 50%

L low; probability of liquefaction < 10%

5-2

STATE UNIVERSITY OF N£W ,",ORK AT BUFFALO

LIQUEFACTION EVALUATION OF MANHATTAN,

NEW YORK CITY, NY,

."OQ"·'WO•I

I

~

FAULT lINE(APPROXJ

N1t

LIQUEFACTION POTENTIAL MAP

Figure 5. Liquefaction potential map for the upper Manhattan study area.

5-3

Approximately one half of the study area has a high to moderate probability of liquefaction.

The high risk areas, as would be expected from the discussion in Section 2.1, are adjacent to the

shore of the Harlem River. The area generally to the north-west of Second Avenue has a low

probability of liquefaction and does not appear to have any significant risk of ground failure.

Even though Ward's and Randall's Islands were included in the study area, they have not been

evaluated because of a lack of SPT values.

5.2.2 Buffalo

The analysis of the Buffalo region has not progressed to the same degree as the study of

Manhattan. The data for the former became available at a much later date than the Manhattan

data. Our examination of the Buffalo data is more qualitative and the evaluations have been

based more on the geological nature of the soils identified in the borehole logs. The

quantitative evaluation of the Buffalo data is continuing.

Fig. 6 shows a preliminary liquefaction potential map of the waterfront area of Buffalo. Two

areas on Kelly Island, an industrialized section of the waterfront, show high probabilities for

liquefaction. These areas contain deposits of very loose silty-sands.

5-4

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SECTION 6

DATABASE DESIGN

As part of the study of the liquefaction potential of New York State, a comprehensive data base

system was designed and largely implemented. The purpose of the data base was to store the

large number of bore hole data which were accumulated during the investigation of that area of

Manhattan bounded by 145th and 96th Streets (East-West), and the Hudson and East Rivers

(North-South), as well as the central part of Buffalo. The total number of soil and SPT values

accumulated from bore hole investigations are on the order of 20,000 for Manhattan alone.

A data base system serves several purposes. Two are of prime importance for this project: 1)

storage of the collected data for future use, and 2) the ability to retrieve selected values for the

evaluation of the liquefaction potential of the two areas in question. Since it is not possible to

foresee future uses for these data, the data base has been designed in a very general manner

allowing easy addition of future applications.

6.1 Specifications

A data base can assume many forms and perform many functions. In view of the complexity of

the liquefaction study described in earlier sections, a relatively small number of functions were

decided upon so as to simplify the design of the data base and facilitate its implementation.

The functions of this minimal data base are:

6-1

Function Operation Current Status

1 STORAGE store geotechnical data from implementeddifferent sites and bore holes

on disk files

2 EDITING the ability to recall data and implementedalter them

3 DISPLAY display stored data as required implementedDATA

4 DISPLAY show the positions of bore partially implementedLOCATIONS holes on a map of the study (Manhattan only)

area

5 DISPLAY show the soil types, geotechni- partially implementedCROSS SEC- cal data, and correlations for

TIONS selected bore holes

6 OUTPUT create an output file containing not implementedDATA selected data for subsequent

analysis

6.2 Implementation

The development of the data base (termed NCEER at present) has proceeded in two phases.

The initial implementation was done in a commercial data base system (dBase III) designed

especially for use on IBM PCs or similar machines. This allowed the authors to rapidly try

various configurations thus gaining experience in the use of the data base. The code was

written in the dBase III language and debugged on an IBM XT equipped with a hard disk and

having 640 kbytes memory. Functions I through 3 were perfected using this system. It was

clear from the start that dBase III would not completely satisfy the requirements for the data

base because the language does not allow graphics output to the computer screen nor graphics

output to a plotter. There are ways around these limitations (principally by using third party

software), but it was decided that this would create a non-standard package that might be

difficult to maintain and modify.

The second phase was to transfer the code developed in dBase III to another language, one

which was capable of handling text data, numerical calculations, and graphics. We chose Pascal

because of the large body of experience gained in this language, and the existence of a very

high quality implementation for the IBM PC (Turbo Pascal). In practice, the transfer of the

6-2

dBase III code to Pascal was relatively simple. On the other hand, the graphics part of the code

(functions 4 and 5) have been more time consuming than was initially thought. The program

presently consists of approximately 2000 lines of code.

6.3 Current Status

At present, the major functions of the code are completely or partially working. The data base

is being used to store the data collected during this first year of work. As far as the authors are

aware, this is the only data base in existence for the storage and manipulation of geotechnical

data related to earthquake hazard assessment. The data base is of general use for the storage of

normal geotechnical data even though it is now being used primarily for the evaluation of

liquefaction potentials.

6.4 Future Activities

Most of our effort during this first year has gone into designing and implementing the data base

code. There remain several major tasks-

1. We have created a minimal data base which is used primarily for testing theprogram; it contains too few bore hole records to serve any practical purpose.Continued work on the data base will focus largely on adding information tothe data base so that we will be able to manipulate any of the thousands ofpieces of information which we have collected to date.

2. We have spent little time working on the code necessary for the subsequentanalysis of the bore hole data (function 6). A major effort will be made tocreate the software necessary to completely analyze the bore hole data of thetwo regions for liquefaction potential.

3. We will modify the program so that it will be capable of a more flexiblegraphics output, both to the monitor Screen and to a printer/plotter.

4. Design ways in which the data base could be made accessible to a widergroup of users. A dial-up access is one such mechanism.

6-3

SECTION 7

CONCLUSIONS

Liquefaction potential maps of two heavily populated urban areas in New York State - upper

Manhattan and central Buffalo - have been assembled from subsurface borehole data. The

liquefaction potential has been determined by a method which is partly empirical and partly

statistical and assumes an earthquake of magnitude 7.5 with a peak ground acceleration of 0.15

g. Given an event of this magnitude and surface acceleration, soils adjacent to the Harlem

River in Manhattan and along the Buffalo waterfront would be highly susceptible to

liquefaction

Many parts of the two study areas, especially those bordering water, are reclaimed land formed

by infilling with assorted debris. It was not possible to evaluate the liquefaction potential of

these areas since we have no historical record of how this type of artificial deposit will behave

when subjected to earthquake stresses. One would suspect that this type of artificial fill would

be likely to amplify earthquake induced ground motions and to shift the frequency spectrum of

the motions to longer periods.

The liquefaction potential maps are not intended to suggest that presently existing structures in

areas which are identified as being underlain by highly liquefiable soils are at risk since such an

evaluation is beyond the scope of the present study. The maps provide useful information for:

I) preliminary structural design considerations, 2) planning of emergency procedures, and 3) the

assessment of land use.

The geotechnical data base which is being assembled in connection with this project should be

expanded to take in larger sections of heavily populated areas in New York State

7-1

SECTION 8

LIMITATIONS

The liquefaction potential maps presented here were zoned into categories of high, medium, and

low liquefaction potential. The zoning criteria however were relative and adopted as per the

opinion of the authors. These maps have some critical limitations with regard to their

interpretation and actual use. The important limitations are :

1. The liquefaction evaluation procedure involved correlations made using datafor other areas in the nation as well as abroad and not from the region ofstudy.

2. The established empmClsms specify a percentage of silt and clay content,whereas the assessment of these quantities at each site was based on thequalitative classifications of the soils. Clean sand or silt layers were notobserved near the surface within the study area. Rather, a mixture ofgravels, sands, silts, and clays are common - the effects of which are nottaken into account in the evaluation procedure. It should be noted that sucheffects have the tendency of reducing the liquefaction potential, making theresults of the present study conservative.

3. The mapping was not attempted for Ward's and Randall's Island, due to sparseand inadequate data. This can be done once adequate data become available.This is also true for the Buffalo map.

4. The maps indicate zones having different liquefaction potentials; this does notnecessarily represent the relative tendency for ground failure. For example,thin subsurface layers having a single low value for the blow count wereconsidered to be liquefiable. Thin layers at greater depths would probablynot cause ground failure even if they liquefy. These layers might, however,cause sand "boiling" which could cause some surface damage.

5. The boundaries of the liquefaction susceptibility zones are approximate.However, it is not necessary to delineate these zones precisely because themethodology itself is imprecise.

6. The liquefaction potentials shown on the preliminary maps presented herewere based on the existence of cohesionless subsurface materials susceptible toliquefaction. There can be sensitive clay layers within the study area whichcould cause damage of different kinds during earthquakes. For example, asensitive clay can amplify the ground motion leading to increased surfacedamage. These materials were not considered in this report.

7. Earthquakes are capable of causing several other kinds of ground failure apartfrom liquefaction. The preliminary liquefaction potential map only coverliquefaction-based ground failures. The evaluation considered soils lyingwithin 50' of the surface. Greater depths could be examined, if necessary,because many of the borelogs go to much greater depths.

8-1

SECTION 9

REFERENCES

1. Acharya, H. (1980) "Spatial Correlation of Large Historical Earthquakes and Moderate Shocks>10 km Deep in Eastern North America": Geophys. Res. Letters, 1, 1061-1064.

2. Algermissen, S. T., D. M. Perkins, P. C. Thenhaus, S. L. Hanson, and B. L. Bender (1982)"Probabilistic Estimates of Maximum Acceleration and Velocity in Rock in the ContiguousUnited States". U.S. Geological Survey, Open File Report 82-1033, 99 p.

3. Anderson, L. R., J. R. Keaton, K. Aubry, and S. J. Ellis (1982) "Liquefaction Potential Mapfor Davis County, Utah", Department of Civil and Environmental Engineering,Utah StateUniversity, Logan, Utah.

4. Barstow, N. L., and P. W. Pomeroy (1984) "Research Required in Support of a ComprehensiveEarthquake Planning and Preparedness Program for New York", Proceedings ofConference XXIX, U. S. Geological Survey, Open File Report 85-386.

5. Coffman, J. L. and Von Hake, C. A. (1973) Earthquake History of the United States: Publ.41-1, U. S. Department of Commerce, Wash. D. C., 208 pp.

6. Fletcher, J. B. and Sykes, L. B. (1977) "Earthquakes Related to Hydraulic Mining and NaturalSeismic Activity in Western New York": J. Geophys. Res., 82, 3767-3780.

7. Fox, F. L. and Spikes, C. T. (1977) "Intensity Ratings of the Attica (N. Y.) Earthquakes ofAugust 12, 1929, a Proposed Reclassification": Earthquake Notes, 48, 37-46.

8. Goldberg-Zoino Associates, Consulting Engineers: (1984) "Preliminary Geotechnical ReportBuffalo Waterfront Study"

9. Hays, W. (1984) "Guidelines for Assessing the Nature and Extent of Earthquake Hazards inthe New York Area and Devising Options for Research and Mitigation". Proceedings ofConference XXIX, U.S. Geological Survey, Open File Report 85-386.

10. Herrmann, R. B. (1978) "A Seismological Study of Two Attica New York Earthquakes": Bull.Seis. Soc. Amer., 68, 641-651.

11. Hodge, D. S., R. Eckert, and F. Revetta (1982) "Geophysical Signature of Central andWestern New York": in Geology of the Northern Appalachian Basin Western New York,Field Trips Guidebook for New York State Geological Association 54th Annual Meeting,3-17.

12. Hutchinson, D. R., Pomeroy, P. W., Wold, R. J., and Halls, H. C. (1979) "A GeophysicalInvestigation Concerning the Continuation of the Clarendon-Linden Fault Across LakeOntario": Geology, 1, 206-210.

13. Idriss, I. M., A. W. Dawson, and M. S. Power (1982) "Evaluation of LiquefactionOpportunity and Liquefaction Potential in the San Diego, California, Urban Area". FinalTechnical Report to the U. S. Geological Survey, Woodward - Clyde Consultants, SanDiego, California.

14. Liao, S. S. c., D. Veneziano, and R. V. Whitman (1987) "Regression Models for EvaluatingLiquefaction Probability," Journal of the Geotechnical Engineers Division, ASCE (inpress)

15. Liao, S. S. C., and R. V. Whitman (1985) "Overburden Correction Factors for SPT in Sand",Journal of Geotechnical Engineering, ASCE, 112 (No.3) 373-377.

9-1

16. Lowe, J. and P. Zaccheo (1975) "Subsurface Explorations and Sampling." Chapter 1,Foundation Engineering Handbook, 1-66, Hans F. Winterkorn and Hsai-Yang Eds., VanNostrand Reinhold Co., New York.

17. McCann, M. W., F. Sauter, and H. C. Shah (1980) "A Technical Note on PGA (Peak GroundAcceleration) - Intensity Relationships with Applications to Damage Estimation". BSSA,V. 70, No.2, 631-637.

18. Mitronovas, W., and G. N. Nottis (1984) "Seismicity of New York: Current Status ofScientific Knowledge and Research in Historical Seismicity:, Proceedings of ConferenceXXIX, U. S. Geological Survey Open File Report 85-386.

19. Power, M. S., A. W. Dawson, D. W. Strieff, R. C. Perman and V. Berger (1982) "Evaluationof Liquefaction Susceptibility in the San Diego, California, Urban Area". Final TechnicalReport to the U.S. Geological Survey, Woodward - Clyde Consultants, San Diego,California.

20. Roth, R. A., and E. Kavazanjian (1984) "Liquefaction Susceptibility Mapping for SanFrancisco, California," Bulletin of the Association of Engineering Geologists, 21(4): 459 ­478.

21. Sbar, M. L. and Sykes, L. B. (1977) "Seismic and Lithospheric Stress in New York andAdjacent Areas": 1.:. Geophys. Res..~ 5771-5786.

22. Seed, H. B., I. M. Idriss, and I. Arango (1983) "Evaluation of Liquefaction Potential usingField Performance Data", Journal of Geotechnical Engineering, ASCE 109 (3): 458-482.

23. Seed, H. B., K. Tokimatsu, L. F. Harder, and R. M. Chung (1984) "The Influence of SPTProcedures in Soil Liquefaction Resistance Evaluations", Report No. UBC/EERC - 84/15,Earthquake Engineering Research Center, University of California, Berkeley, California.

24. Smith, W. E. T. (1962) "Earthquakes of Eastern Canada and Adjacent Areas, 1534-1927":PubI. 26, Dominion Observatory, Ottawa, Canada, 271-301.

25. Sykes, L. R. (1978) "Intraplate Seismicity Reactivation of Pre-existing Zones of Weakness,Alkaline Magmatism, and Other Tectonism Postdating Continental Fragmentation": Rev.Geophys. and Space Phys., lQ, 621-688.

26. Tinsley, J. G., T. L. Youd, D. M. Perkins, and A. T. F. Chen (1985) "EvaluatingLiquefaction Potential," Evaluating Earthquake Hazards in the Los Angeles Region, anEarth Science Perspective, Professional Paper 1360, J. I. Ziony, ed., U. S. GeologicalSurvey.

27. Veneziano, D. and J. Van Dyck (1984) "Analysis of Eastern United States Seismicity on aOne-Degree Grid: Incompleteness, Recurrence Rates, and Non-Stationarity". ElectricPower Research Institute, Palo Alto, California, 149 pp.

28. Youd, T. L., and S. N. Hoose (1977) "Liquefaction Susceptibility and Geologic Setting",Proceedings of the Sixth World Conference on Earthquake Engineering, V. 3, PrenticeHall, Inc., Englewood Cliffs, New Jersey, 2189-2194.

29. Youd, T. L., and M. Perkins (1978) "Mapping Liquefaction Induced Ground FailurePotential," Journal of the Geotechnical Engineering Division. ASCE 104 (GT4):433 - 446.

30. Youd, T. L., and J. B. Perkins (1985) "Map Showing Liquefaction Susceptibility in SanMateo County, California," Miscellaneous Investigations Series Map I -1257-G, U. S.Geological Survey, Menlo Park, California.

9-2

31. Youd, T. L., J. C. Tinsley, D. M. Perkins, E. J. King, and R. F. Preston (1978)"Liquefaction Potential Map of San Fernando Valley, California." in Proceedings of theSecond International Conference on Microzonation for Safety Construction - Research andApplications, V. I, National Science Foundation, Washington, D.C., 268-278.

9-3

SECTION 10

ACKNOWLEDGMENTS

The authors are particularly indebted to a number of people who helped us assemble the data

needed for this study. These are-

Mr. Aroon ShawChief Structural Engineerand Mr. Andrew BersonNew York City Housing Authority

Mr. J. BIasManagerEmpire Soils Investigations, Inc.

Mr. Michael GreenmanGeologistDept. of General ServicesMunicipal BuildingNew York City

Mr. John LafredoCity EngineerCity of Buffalo

Mr. Steve PulleyGeotechnical/Materials EngineerEmpire Soils Investigations, Inc.

Mr. James SegunComputer AnalystCity of Buffalo

10-1

SECTION 11

APPENDICES

Appendix IA and IB are sections from a Lotus spread sheet which was used to do the

calculations of the liquefaction potential - IA lies directly to the left of IB in the original

configuration. Not all of the borehole data are shown. The headings for the columns are self

explanatory except for the following.

Ref. this is the site number on the original borehole log

Number

Sampler

Hammer

Correction

for SPT

Prob. liq

the sampler hammer ratio, Rs, from equation (1),

Section 2.2.2.

the stress reduction coefficient in equation (3),

Section 2.2.3.

the correction factor from equation (2), Section

2.2.2.

the correction factor to normalize the overburden

pressure (0".;1/2) with 0"0 in tsf.

corrected normalized SPT. The x ordinate of Fig.

1 and Fig. 2

average cyclic shear stress in equation (3)

the probability of liquefaction for the susceptible

layer from Fig. 2

11-1

~ ~

I~

App

endi

xlA

.Sa

mpl

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tfo

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ils.

Ref

.E

lev.

LAT.

(N)

LONG

(W)

Hal

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rH

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Sam

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Log

Sh

ift

Log

Posi

tion

Sur

face

G.

IJ.

Sus

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.L

ayer

NLJ

Tber

Ref

.40

deg

+73

deg

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all

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Lat

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LAT.

LONG

.el

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Mea

nSL

II

(lb

s)(i

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(in

)(f

t)-

-45

2.75

047

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054

47/6

030

018

.00

2.50

1.16

E'0

55.

0010

8-1

1347

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54.7

592.

202.

20-5

.80

-10.

80

722.

608

4813

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5421

/60

265

18.0

02.

501.

32E

-05

SES

6·1

450

1840

47.9

7554

.750

6.7

1.7

-1.3

-6.3

4813

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5421

/60

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18.0

02.

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SES

8·7

5010

5048

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54.5

796.

400.

80-1

.60

-5.6

0

4813

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18.0

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·05

SES1

2-7

545

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54.4

486.

101.

70-7

.90

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90

300

18.0

02.

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0.00

00.

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6.10

1.70

-17.

90-2

1.90

4813

/60

5421

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18.0

02.

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664

0-4

9048

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54.2

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.60

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60

265

18.0

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0.00

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1.80

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60-2

5.60

106

2.75

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055

47/6

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0.00

0.00

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00-6

9.00

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5547

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300

18.0

02.

501.

16E

·05

14.0

017

0·5

848

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55.7

716.

100.

00'1

2.9

0-2

6.90

108

2.75

4851

/60

566/

6030

018

.00

2.50

1.16

E·0

52.

0050

-112

48.8

5856

.076

5.20

-1.4

0'1

5.8

0-2

8.80

300

18.0

02.

501.

16E

·05

0.00

00.

000

5.20

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0-2

8.80

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80

4851

/60

566/

6030

018

.00

2.50

1.16

E·0

510

.00

-13

238

48.8

4856

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7.50

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0-1

4.50

-37.

50

300

18.0

02.

501.

16E

-05

0.00

00.

000

7.50

-1.3

0-3

7.50

-77.

50

4851

/60

566/

6030

018

.00

2.50

1.16

E-0

515

.00

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-250

48.7

9056

.046

7.10

-1.2

0-1

5.90

-29.

90

300

18.0

02.

501.

16E

-05

0.00

00.

000

7.10

-1.2

0-2

9.90

-42.

90

110

?49

10/6

056

2/60

300

18.0

02.

501.

16E

-05

2.00

-42

-60

49.1

6056

.020

6.00

-1.3

0'2

.00

-16.

00

300

18.0

02.

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16E

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0.00

00.

000

6.00

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0-1

6.00

-44.

00

111

2.75

048

25/6

056

3/60

300

18.0

02.

501.

16E

-05

6.00

-20

-70

48.4

1356

.035

7.50

'0.5

0-1

6.50

-24.

50

300

18.0

02.

501.

16E

-05

0.00

00.

000

7.50

'0.5

0-2

4.50

-32.

50

134

2.75

048

54/6

057

23/6

030

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53A

00

48.9

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30.0

020

.00

20.0

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6056

44/6

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537

.00

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56.7

338.

20-1

.60

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.80

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.80

476/

6056

44/6

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1.16

E-0

549

.00

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-120

47.0

5356

.707

6.60

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0-6

.40

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.40

300

18.0

02.

501.

16E

-05

0.00

00.

000

6.60

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0-1

7.40

-33.

40

300

18.0

02.

501.

16E

-05

0.00

00_

000

6.60

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0-3

3.40

-58.

40

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6056

44/6

030

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2.50

1.16

E-0

569

.00

-30

-760

47.0

9556

.568

7.80

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0'2

0.2

0'2

6.2

0

300

18.0

02.

501.

16E

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0.00

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7.80

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0-2

6.20

-43.

20

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6056

44/6

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.00

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1.16

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510

7.00

4813

047

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56.7

629.

50'0

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0-1

7.50

300

18.0

02.

501.

16E

-05

0.00

00.

000

9.50

-0.8

0-1

7.50

-25.

50

300

18.0

02.

501.

16E

-05

0.00

00.

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9.50

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0'2

5.5

0-5

0.50

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.511

55.0

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81.

212.

422.

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0.21

881

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0.97

5.0

10.5

1155

.081

1.8

1.32

22.4

51

.57

350.

134

0

20.0

05

SM0.

974.

010

.011

00.0

825.

41.

326.

601.

5610

0.12

630

20.0

07

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9610

.019

.020

90.0

1179

.01.

218.

451.

3011

0.16

640

11SP

0.94

4.0

26.0

2860

.015

12.2

1.21

13.2

81.

1515

0.17

330

100.

0050

.00

5ML

0.96

6.0

16.0

1760

.098

6.2

1.32

6.60

1.42

90.

167

50

40SW

0.94

12.0

25.0

2750

.014

14.6

1.32

52.8

31.

1963

0.17

80

100.

0050

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0.80

36.0

51.0

5610

.024

27.6

1.21

12.0

80.

9111

0.18

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10SP

0.94

14.0

26.0

2860

.016

18.2

1.21

12.0

81.

1113

0.16

240

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.530

25.0

1720

.81.

217.

251.

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0.16

152

20.0

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7057

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75.0

3386

.81.

2114

.49

0.77

110.

139

30

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0.91

23.0

33.5

3685

.021

43.7

1.21

9.66

0.97

90.

153

65

20.0

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7040

.065

.071

50.0

3643

.11.

219.

660.

747

0.13

445

11SP

0.93

14.0

30.0

3300

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45.9

1.21

13.2

81.

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0.15

430

20.0

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8413

.043

.547

85.0

2588

.51.

2113

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0.88

120.

151

32

4SP

0.96

14.0

15.0

1650

.011

69.5

1.21

4.83

1.31

60.

131

70

20.0

020

.00

10ML

0.89

28.0

36.0

3960

.021

69.1

1.21

12.0

80.

9612

0.15

932

7SP

0.92

8.0

28.0

3080

.018

32.0

1.21

8.45

1.04

90.

150

65

13SP

0.89

8.0

36.0

3960

.022

12.8

1.21

15.7

00.

9515

0.15

618

5.00

39SP

0.96

18.0

19.0

2090

.015

28.4

1.21

47.0

91.

1454

0.12

80

10SW

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